TEHRAN, Apr. 17 (Press Shia Agency) –Syrian sources relayed that investigators of the Organization for the Prohibition of Chemical Weapons (OPCW) entered the Syrian town of Douma, on Tuesday afternoon, to conduct probe on what terrorist claim to be a chemical attack by government.

According to Syrian sources, investigators of the Organization for the Prohibition of Chemical Weapons (OPCW) have entered the Syrian town of Douma, on Tuesday afternoon local time. OPCW is tasked with examining the alleged chemical weapons attacks.

OPCW personnel arrived in Syria on Saturday to investigate a suspected chemical weapons attack in Douma, which US and some Western countries claim was committed by the Syrian government.

Russia had previously said the investigators would be allowed to access the site of the attack on Wednesday and it was not immediately clear whether their work would begin on Tuesday or Wednesday. The OPCW has so far not independently confirmed reports of their team’s arrival.

While Syria, Russia, and Iran are continuing to reject responsibility for the attack, providing evidence that US-backed terrorists carried out a chemical attack for westerners’ support, the OPCW is now the only organization that is supposed to reach an impartial assessment.

Also the Syrian government has offered the OPCW access to what it said were 22 witnesses of the attack and the OPCW investigation relies on probes that can be conducted only on the site of a suspected attack. While in Douma, the investigators are expected to gather soil samples that could ultimately be used to determine which chemicals were used.

“What you’re trying to do is a combination of things: You try to investigate the actual location that was impacted, which gives you a clue of what the site looks like and whether you can find remnants of the weapons themselves,” said Ralf Trapp, an international disarmament expert who has worked with the OPCW.

Also on Monday, the OPCW Director-General addressed the OPCW Executive Council and welcomed that all delegations taking the floor supported the deployment of the Fact-Finding Mission (FFM) to Douma and expressed their full confidence in the work of the FFM.